题解 | #删除记录(二)#
删除记录(二)
http://www.nowcoder.com/practice/964c9f7fffbb4ab18b507cfed4111b4a
limit 5 返回前五行数据
limit 5,10 返回五到十行的数据
delete from exam_record where submit_time is null&nbs***bsp;timestampdiff(minute, start_time, submit_time) < 5 order by start_time limit 3